The overall objectives of the project are to describe the functions of fibronectin and other pericellular matrix proteins and to define their role in malignant transformation. We are studying: 1. the structure and biosynthesis of fibronectin, 2. pericellular matrix components, in particular fibronectin, laminin, basement membrane collagens, and heparin sulfate proteoglycan of various types of adherent cells in culture, 3. matrix proteins in embryonic development, 4. human fibronectin in vivo under normal and pathological conditions, 5. interactions of malignant cells with pericellular matrix proteins, and 6. the possibility that pericellular proteolysis is regulated by alpha2-macroglobulin in normal but not in malignant cells.